javascript - 网格的字段绑定(bind)。将新记录添加到 Store 后 View 仍然不一致

标签 javascript java gridview gwt gxt

我们为应用程序中的一些典型网格用法实现了绑定(bind)。它工作得很好,除非你修改商店,例如添加一条记录,你会在 View 中看到 n + 两条相同的记录。 当我检查商店的状态时,它显示了 n + 1 个值。

就好像我有一个网格,其中显示了一条记录并调用:grid.getStore().add(modelFactory.createModel(event.getBean())); 我现在有:

Second and third lines ARE equal

第二行和第三行相等,不能选择第三行。此外,它不存在于 grid.getStore() 中。

来源:

freqsGrid = new AwesomeGridPanel() {
    @Override
    public void createColumns() {/**/}
};
freqBinding = AwesomeGridBinding.createGridBinding(freqsGrid, "frequencies");

简单的绑定(bind)源。它将模型的 List 属性按原样映射到网格。

public class AwesomeGridBinding {
    public static FieldBinding createGridBinding(AwesomeGridPanel grid, String property) {
        return new FieldBinding(new AwesomeGridAdapterField(grid), property);
    }
}

class AwesomeGridAdapterField<T> extends AdapterField {

    protected AwesomeGridPanel grid;
    private StoreListener<BeanModel> storeChangedListener;

    public AwesomeGridAdapterField(AwesomeGridPanel grid) {
        super(grid);
        this.grid = grid;
        configureGrid(grid, this);
    }

    @Override
    public void setValue(Object value) {
        List data;
        if (value == null)
            data = new ArrayList<>();
        else if (!(value instanceof List))
            throw new IllegalArgumentException();
        else
            data = (List) value;
        grid.getStore().setMonitorChanges(false);
        grid.getStore().setFiresEvents(false);
        setResults(grid.getStore(), data);
        grid.getStore().setFiresEvents(true);
        grid.getStore().setMonitorChanges(true);

如果我删除下面的行, View 将在添加后停止显示 n+2 行,并且甚至在 formBinding.bind(createModel(bean)); 之后开始显示添加的行到另一个 bean。

        grid.getGrid().getView().refresh(false);
    }

    @Override
    public Object getValue() {
        List<T> result = new ArrayList<>();
        for (BeanModel bm : grid.getStore().getModels())
            if (isBeanForResult(bm))
                result.add(extractResult(bm));
        return result;
    }

    protected void setResults(ListStore<BeanModel> store, List data) {
        store.removeAll();
        for (Object obj : data)
            if (obj instanceof BeanModel)
                store.add((BeanModel) obj);
            else
                throw new IllegalArgumentException();
    }

    protected boolean isBeanForResult(BeanModel beanModel) {
        return true;
    }

    protected T extractResult(BeanModel bmFromStore) {
        return bmFromStore.getBean();
    }

    private final EventType[] STORE_EVENTS = {Store.Add, Store.Clear, Store.DataChanged, Store.Remove, Store.Update};

    protected void configureGrid(final AwesomeGridPanel grid, final AdapterField field) {
        grid.getStore().setMonitorChanges(true);
//        grid.getStore().removeAllListeners();
        if (storeChangedListener != null)
            grid.getStore().removeStoreListener(storeChangedListener);

        storeChangedListener = new StoreListener<BeanModel>() {
            @Override
            public void handleEvent(StoreEvent<BeanModel> e) {
                super.handleEvent(e);
                for (EventType se : STORE_EVENTS) {
                    if (se != e.getType())
                        continue;
                    field.fireEvent(Events.Change);
                    return;
                }
            }
        };
        grid.getStore().addStoreListener(storeChangedListener);
    }
}

最佳答案

我发现解决问题的唯一方法是避免商店修改。 我使用了 BeanModel。

小部件:

schedulesGridPanel = new AwesomeGridView<RcTaskSchedule>(ListBinding.createEmptyStore(), NavigationTarget.RADIOCONTROL_TASK_DIALOG, "RCTaskDialogSchedulesGridPanel") {
    @Override
    public void createColumns() {...}
};
formBinding.addFieldBinding(new ListBinding(schedulesGridPanel.getGrid(), "schedules"));

...

@Override
public BeanModel getBeanModel() {
    return (BeanModel) formBinding.getModel();
}

... 主持人:

eventBus.addBeanCreatedEventHandler(RcTaskSchedule.class, NavigationTarget.RC_TASK_SCHEDULE_DIALOG, new BeanCreatedEvent.Handler<RcTaskSchedule>() {
    @Override
    public void onBeanCreated(BeanCreatedEvent<RcTaskSchedule> event) {
        ListBinding.addListItemInBeanModel(display.getBeanModel(), "schedules", schedulesFactory.createModel(event.getBean()));
    }
});

eventBus.addBeanModifiedEventHandler(RcTaskSchedule.class, NavigationTarget.RC_TASK_SCHEDULE_DIALOG, new BeanModifiedEvent.Handler<RcTaskSchedule>() {
    @Override
    public void onBeanModified(BeanModifiedEvent<RcTaskSchedule> event) {
        ListBinding.updateListItemInBeanModel(display.getBeanModel(), "schedules",
                schedulesFactory.createModel(event.getOldBean()), schedulesFactory.createModel(event.getModifiedBean()));
    }
});   

...

public class ListBinding extends FieldBinding {

    private Grid grid;
    private ChangeListener listener = null;
    private MemoryProxy memoryProxy = null;

    public ListBinding(Grid grid, String property) {
        super(new AdapterField(grid), property);
        this.grid = grid;
        if (!(grid.getStore().getLoader() instanceof BaseListLoader))
            return;
        BaseListLoader loader = (BaseListLoader) grid.getStore().getLoader();
        if (!(loader.getProxy() instanceof MemoryProxy))
            return;
        memoryProxy = (MemoryProxy) loader.getProxy();
    }

    @Override
    public void bind(ModelData model) {
        super.bind(model);

        if (memoryProxy == null)
            return;
        grid.getStore().removeAll();
        memoryProxy.setData(getModel().get(getProperty()));
        grid.getStore().getLoader().load();

        if (!(model instanceof BeanModel))
            return;
        BeanModel bm = (BeanModel) model;

        listener = new ChangeListener() {
            @Override
            public void modelChanged(ChangeEvent event) {
                if (!(event instanceof PropertyChangeEvent))
                    return;
                if (!property.equals(((PropertyChangeEvent) event).getName()))
                    return;
                grid.getStore().removeAll();
                memoryProxy.setData(getModel().get(getProperty()));
                grid.getStore().getLoader().load();
            }
        };
        bm.addChangeListener(listener);
    }

    @Override
    public void unbind() {
        super.unbind();
        grid.getStore().removeAll();
        if (listener == null)
            return;
        if (!(this.getModel() instanceof BeanModel))
            return;
        BeanModel bm = (BeanModel) this.getModel();
        bm.removeChangeListener(listener);
    }

    public static ListStore<BeanModel> createEmptyStore() {
        return new ListStore<>(new BaseListLoader(new MemoryProxy(new BoundList<>())/*, new BeanModelReader()*/));
    }

    public static void addListItemInBeanModel(BeanModel beanModel, String property, BeanModel newItem) {
        if (beanModel == null || !(beanModel.get(property) instanceof List) || newItem == null)
            return;
        List<BeanModel> list = beanModel.get(property);
        list.add(newItem);
        beanModel.set(property, null);
        beanModel.set(property, list);
    }

    public static void updateListItemInBeanModel(BeanModel beanModel, String property, BeanModel oldItem, BeanModel newItem) {
        if (beanModel == null || !(beanModel.get(property) instanceof List) || newItem == null || oldItem == null)
            return;
        List<BeanModel> list = beanModel.get(property);
        int index = list.indexOf(oldItem);
        if (index < 0)
            return;
        list.set(index, newItem);
        beanModel.set(property, list);
    }

    public static void removeListItemsInBeanModel(BeanModel beanModel, String property, List<BeanModel> items) {
        if (beanModel == null || !(beanModel.get(property) instanceof List) || items == null || items.isEmpty())
            return;
        List<BeanModel> list = beanModel.get(property);
        list.removeAll(items);
        beanModel.set(property, list);
    }

}

关于javascript - 网格的字段绑定(bind)。将新记录添加到 Store 后 View 仍然不一致,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/32582099/

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